JP2002323988A - Method and system for processing remote interrupt signal, and network interface system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To process an interrupt that occurs in a remote node connected to a network. SOLUTION: When the interrupt occurs in the remote node, a raw packet including the address of a host device that should process the interrupt and an event identifier is selected among preprepared raw packets and transmitted to a host node through the network 115.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to remote interrupts, and more particularly, to issuing raw packets on a network in response to remote interrupts.

[0002]

2. Description of the Related Art An interrupt is a signal that notifies a host device or a program that a specific event has occurred. If the host receives an interrupt signal, the host can take the specified action or simply ignore the interrupt signal. Certain interrupt signals can be assigned a higher priority than other interrupt signals or processes. That is, a high priority interrupt signal
While the higher priority interrupt is being serviced, lower priority processing can be temporarily halted. Briefly, an interrupt signal can be generated by hardware or software, thereby indicating that an event has occurred. However, for an interrupt signal to serve its intended purpose, the interrupt signal must be received by a device that can interpret the interrupt and take the corresponding action.

In a conventional computer system, input / output
Interrupts generated by output devices (IO devices) or computer applications are typically handled by an interrupt controller and central processing unit (CPU) local to the interrupt device. The local host CPU responds to interrupt requests from each device type coupled to the local host bus. IO devices can be coupled to the interrupt controller by direct lines or by shared lines. The interrupt controller receives the interrupt requests and provides them to the CPU along with the number of the interrupt associated with the interrupt. Thus, processing of an interrupt request requires an intelligent host device, such as a host CPU, local to the interrupt device.

[0004] This requirement for intelligent devices can be problematic. For example, consider a network environment having remote nodes that include only some unintelligent IO devices coupled to a network via a network interface card (NIC). Each IO device has a unique set of requirements for notifying the host CPU node of an interrupt request. That is, to store various parameters for each supported IO device, the remote N
A dedicated register included in the IC is used. In this manner, the remote interrupt can be processed using the remote NIC.

However, each operation performed by an IO device may have a different set of interrupt parameters or requirements. Further, each IO device may have various interrupt requirements that are different from the interrupt requirements of other IO devices at that node. Thus, the variety of IO devices and the operations performed by each of those IO devices can require a significant amount of register space on the remote NIC. One solution to this problem is to simply limit the number of support operations for each IO device. However, such a solution is not always desirable and practical. Furthermore, if the interrupt requirements of an IO device are not known or apparent, a remote NIC cannot be configured for that device.

[0006]

Therefore, what is needed is a technique for handling interrupts that occur at remote and unintelligent nodes. This technique must be flexible to accommodate multiple and diverse interrupt requirements and various interrupt devices and events.

[0007]

SUMMARY OF THE INVENTION One embodiment of the present invention provides a method for handling a remote interrupt signal. The method includes receiving an interrupt signal at a remote node from an interrupt signal source. Further, the method includes selecting a raw packet based on the received interrupt signal, wherein the raw packet includes an identifier of the interrupt signal source. The method further includes sending the selected raw packet from the remote node to the host node over the network.

Another embodiment of the present invention provides a system for issuing raw packets over a network in response to a remote interrupt. The system includes a host node that includes a processing unit. The host node is operatively coupled to the network and is for receiving issued raw packets. This embodiment of the system further includes a remote node that includes a network interface module and an interrupt signal source. The network interface module is for issuing a raw packet based on the interrupt signal received from the interrupt signal source. The raw packet contains the interrupt source identifier.

[0009] Another embodiment of the present invention provides a network interface system. The network interface system includes a raw packet buffer for storing a number of raw packets, each raw packet comprising:
Contains the identifier of the corresponding interrupt signal source. In response to the interrupt source supplying the interrupt signal to the network interface system, the network interface system issues a corresponding raw packet to the host node via the network.

[0010] Not all features and advantages described herein are all-inclusive, and many additional features and advantages will be apparent to those skilled in the art, especially in light of the drawings, specification and claims. It will be. Furthermore, it is pointed out that the terms used herein have been chosen primarily for readability and explanatory purposes and do not limit the scope of the inventive subject matter.

[0011]

FIG. 1 is a block diagram of a system capable of sending raw packets in response to a remote interrupt according to one embodiment of the present invention. The system is network 1
15 includes a host node associated with a remote node. The host node includes a central processing unit (CPU) 105 operatively coupled to a network interface card (NIC) 110 by a host bus. On the other hand, the remote node includes a NIC 120 operatively coupled to the CPU 125 and some input / output (IO) devices 130 (eg, 130a and 130b), such as by a system bus or IO bus. Each of the devices included in the remote node can generate an interrupt signal, whether a hardware or software interrupt.

It should be noted that several different alternative embodiments can be configured and the invention is not intended to be limited to any one particular embodiment or configuration. For example, the remote node is the CPU 12
5 or one or more CPUs 12
5 may be included. Further, there can be any number of nodes associated with network 115. In one embodiment, the remote node includes a single IO device 130 that integrates the functions of the network card 120. The host bus of the host node as well as the system / IO bus of the remote node may be a Peripheral Component Interconnect (PCI) bus or other conventional bus technology. Other embodiments and configurations are apparent in light of the present disclosure.

Generally, an event occurs at a remote node that triggers an interrupt signal to be generated. The interrupt signal source may be from any of the devices included in the remote node. For example, the interrupt signal is generated by the program when the program executed by the CPU 125 requests that the CPU 105 of the host node perform something, for example, providing data to the program. Similarly, the interrupt signal is generated by an IO device 130, such as a printer, that has received a print request but has run out of paper. There are many other factors that cause the interrupt signal to be generated by the CPU 125, the IO device 130, or the like.
Generally, an interrupt is generated by an error, operation completion (eg, completion of a direct memory access), or other special event.

Regardless of why the interrupt signal is generated, the host node (eg, CPU 105) must recognize the interrupt so that a response operation can be taken. If the interrupt was not communicated to the host node, it would simply be ignored, as if no interrupt was generated, probably with undesirable consequences. In the illustrated embodiment, NIC 120 includes:
By issuing or "sending" a raw packet prepared by the host node, one of the interrupt signal sources
Respond to an interrupt signal generated by the For example,
The raw packet can specify the address of the processing host device, the identifier of the device or event associated with the generated interrupt signal, and other relevant information needed by the host to process the interrupt request. For example, the raw packet also includes information about the interrupting device or status code associated with the interrupting device.

[0015] Raw packets may be transmitted during an initial system setup session or at a new interrupt source (eg,
When CPU 125, IO device 130 or certain events) are added to the system, they can be provisioned by host software, hardware, firmware or any combination thereof. Once the raw packet is prepared, the raw packet is sent to the corresponding remote node (eg, NIC
120) and stored. In the illustrated embodiment, the prepared raw packets are stored in a buffer included in NIC 120. When one of the remote interrupt signal sources generates an interrupt signal, that signal is received by NIC 120.

Note that the interrupt signal may be represented in several ways, for example, in the form of an electrical signal (eg, a logic high or low signal) or by the occurrence of an event (eg, the passage of a timer). NIC 120 responds to the interrupt signal by issuing a raw packet corresponding to that particular interrupt signal. This raw packet is transferred over the network 115 and received by the host node. Next, the host node (for example, CPU
105) can examine the raw packet, evaluate the associated interrupt request, and take action.

FIG. 2 is a schematic block diagram of a remote network interface system according to one embodiment of the present invention. As can be seen, this embodiment of NIC 120 includes a raw packet buffer 205. This raw packet buffer 205 stores several raw packets (for example,
Raw packet 0, raw packet 1, raw packet 2, etc.). Each of these raw packets is associated with a particular interrupt line, and each interrupt line is associated with a particular interrupt signal source (eg, IO device 130, CPU 135 or event). In response to the activation of the interrupt line, an associated raw packet is issued to the network 115. As previously shown, raw packet buffer 2
05 is prepared in advance during a system setting session or the like, and then the raw packet buffer 2
05 is provided to the NIC 120 for storage.

In one embodiment, the raw packet buffer 20
5 is a static random access memory (SRAM)
Is realized. However, the raw packet buffer 205 can be implemented using other memory means. For example, raw packet buffer 205 may be implemented with a dynamic random access memory. Alternatively, raw packet buffer 205
Can be implemented with a non-volatile memory such as a flash memory chip or an electronically erasable programmable read only memory (EEPROM). Alternatively, the raw packet buffer may be a linked list of data structures, each corresponding to the contents of a particular raw packet. in short,
The raw packet buffer 205 may be implemented using any storage medium (eg, hardware, software, firmware) that provides addressable or otherwise indexable content.

FIG. 3 is a detailed block diagram of a remote network interface system according to an embodiment of the present invention. This embodiment of NIC 120 includes a raw packet buffer 205, a packet receiver 210, a packet assembler 215, and some state machines 220 (eg, S
M0, SM1, SM2, SMN), pointer selector 2
25, an interrupt controller 230 and an interface 235 to the packet preparation means. For example, each of these components may be implemented in hardware, software, firmware, or any combination thereof. These components can be physically realizable independently of each other (eg, individual modules or integrated circuits), or can be realized on a single integrated circuit or chipset, or the like.

The packet receiver 210 receives a packet (called a network packet) from the network,
Extract information from the packet and send the information to NIC12
Make it comprehensively available to 0. In the illustrated embodiment,
Information extracted from the network packet includes state information. This state information is then provided to state machine 220 via a state output. For example, the packet receiver 21
A status output of 0 may indicate a normal, error or retry status. Normal indicates that the transfer of the previous raw packet was successful and that there is currently no abnormal condition. However, an error or retry status indicates that a previously transmitted raw packet was rejected. The error condition specifies that the previously sent raw packet was defective or otherwise related to an error condition, while the retry condition indicates that the target node of the previously sent raw packet was busy or Specifies that it could not be used. In either case, the interrupt request can be tried multiple times until this transfer is successful and acknowledged. A counter may be used in state machine 220 to keep track of the number of retries and prevent a permanent repeated state.

The interrupt controller 230 is coupled to an interrupt line from an interrupt signal source such as an IO device and a software application. Interrupt controller 230 receives the interrupt request and makes the interrupt request to corresponding state machine 220. For example, if the interrupt line associated with interrupt 2 is received, the interrupt controller provides this interrupt request to SM2 of state machine 220. In one embodiment, each interrupt line received by interrupt controller 230 is associated with a state machine 220 (eg, interrupt line 0).
Corresponds to SM0, interrupt line 1 corresponds to SM1, interrupt line 2 corresponds to SM2, and so on). However, the interrupt lines received by the interrupt controller 230 may also share a particular state machine 220 (eg, interrupt lines 0 and 1 may correspond to SM0). The number of interrupt line / state machine pairs depends on factors such as the variety of interrupt sources and the various interrupt requirements associated with the interrupt sources.

State machine 220 includes a set of states (eg, initial state, current state, and next state), a set of input events, a set of output events, and state transition functions. The state transition function takes a current state and an input event and returns a new set of output events and the next state. In the illustrated embodiment, the input events for each state machine 220 include the output of the interrupt controller 230 and the state output of the packet receiver 210. The output events for each state machine 220 include the request associated with the received interrupt request and some raw packet selector outputs. Output event and next state values depend on the state machine and the current state of the input event. In general,
State machine 220 maps an ordered set of input events to a corresponding set of output events.

In one embodiment, state machine 220 maintains a counter that tracks the number of times a raw packet is transferred in response to a particular interrupt request. Raw packets rejected by the host node may need to be retransmitted, for example, due to a transmission error or because the host node was busy as specified by the status output of packet receiver 210. If the current state of the state machine 220 indicates that the raw packet has been retried a maximum number of times (eg, due to an error or radiation), the corresponding output event and the next state will continue to retry the request. And record the error. In view of the present disclosure, another form of counter for state machine 220 is apparent. For example, a raw packet rejected for a reason based on radiation is retried multiple times, while a raw packet rejected for an error-based reason is not retried at all. An error condition is logged immediately or otherwise signaled to the system administrator or user.

The pointer selector 225 is a state machine 2
The output of the raw packet selector 20 is converted to an address identifying the position of the corresponding raw packet in the raw packet buffer 205. The selected raw packet is then provided to packet assembler 215, along with the request associated with the received interrupt signal. Next, the packet assembler 215 generates a network packet that includes the request associated with the raw packet and the received interrupt signal that includes the identifier of the requesting device. The output of the packet assembler 215 is operatively coupled to the network 115, thereby enabling assembled network packets to be transferred over the network 115 to a host node. Note that network 115 can be a local area network of a home or office or a wide area network (including the Internet) that spans multiple offices or homes.

The interface 235 interfaces the packet preparation means to the raw packet buffer 205 of the NIC 120. For example, the interface 235 receives the raw packet prepared from the packet preparing unit.
232C data port. However, RS-42
2, other serial port technologies such as RS-423, USB and IEEE 1394 can also be used in this embodiment. Further, the interface 235 can be realized by using a parallel port technology such as a SCSI port, a Centronics type port, an enhanced parallel port, and an extended capability port. In one embodiment, the packet preparation means is a software program running on the host node. The software program can receive interrupt requirement information for each interrupt source during a configuration session (eg, when each interrupt source is added or otherwise introduced to the system). The prepared raw packet can then be provided to the raw packet buffer 205 via the interface 235.

In an alternative embodiment, interface 235
May be a packet receiver that receives network packets, including prepared raw packets. Raw packets are extracted from the received network packets and then provided to raw packet buffer 205. In one such embodiment, interface 235 is included in packet receiver 210, which is coupled to raw packet buffer 205 and connects to network 115.
Can be programmed or otherwise configured to extract raw packets from network packets received from Next, the extracted raw packet is provided from the packet receiver 210 to the raw packet buffer 205.

FIGS. 4 and 5 are flowcharts illustrating a method for processing a remote interrupt signal according to one embodiment of the present invention. For example, the method can be implemented by a state machine such as state machine 220 of FIG. However, such as a set of software instructions running on a conventional CPU or microcontroller,
There are several processing environments available to perform this method, and the invention is not intended to be limited to one particular embodiment.

The method begins with receiving 305 an interrupt signal from an interrupt signal source, such as an IO device or a software application. The method proceeds to raw packet selection 310 based on the received interrupt signal.
In one embodiment, if the buffer location containing the corresponding raw packet is otherwise not available, the process repeats the selection step multiple times until a raw packet associated with the received interrupt signal is available. Steps may be included. The raw packet contains information such as the identifier of the requesting device or event that the host node needs to process or respond to the interrupt request.

The method includes issuing a selected raw packet 3
15 is further included. In one embodiment, the selected raw packet is embedded in a network packet and forwarded over the network to the host node. The network packet may also include the address or identifier of the intended recipient, and other information such as requests, instructions or instructions related to the received interrupt signal. The method is
A wait 320 waiting for a response from the host may also be included. For example, the response may indicate that a network packet, including the selected raw packet, has been received and responded accordingly. Alternatively, the response may indicate that the transfer of the network packet was unsuccessful due to radiation (eg, the host node was busy) or an error (eg, a defective packet).

In one embodiment, the method further includes determining 325 whether the issued raw packet was rejected. For example, the decision can be based on a response received from the host node. The method may further include determining 330 whether the issued raw packet was rejected due to a radiation. If the issued raw packet was rejected due to radiation, the method may include increasing the retry counter 335. The retry counter provides a means for keeping track of how many times a particular raw packet has been issued in response to a particular interrupt request. In such embodiments, the method may further include determining 340 whether the retry counter is at its maximum allowable value. If the retry counter is at its maximum allowed value, no further retries are attempted. Rather, the method uses the error record 34
Go to 0.

On the other hand, if the raw packet was rejected for some other reason, not for the radiation, then the method should be used for error record 3
Proceed to 40. In this case, the packet may have been rejected, for example, due to a packet defect. Further, if a maximum value of the time that elapses without a response from the host node is set, a timeout state can be indicated. in this case,
The method may include indicating a timeout condition by recording a timeout error or displaying a timeout message. Note that in an alternative embodiment, a retry counter for failures associated with non-radiation events may be provided, thereby allowing multiple retries in the event of such failures.

The above description of the embodiments of the present invention
They are provided for illustration and explanation. This description is not intended to be exhaustive of the precise form disclosed, or to limit the invention to that form.
Many modifications and variations are possible in light of the above, as will be appreciated by those skilled in the art.

For example, the function of the NIC 120 can be realized by a microcontroller unit (MCU).
In this case, the interrupt line from the interrupt signal source can be coupled to the MCU's IO port. The MCU includes a processor that can execute one instruction set stored in a nonvolatile memory included in the MCU. Also, the raw packet buffer 205 could be stored using this memory. Depending on the instruction set, state machine 220, packet receiver 210,
Packet assembler 215 and pointer selector 22
Functions such as 5 can be realized. Raw packet buffer 205 may also be implemented by software-based memory. In addition, the MCU provides a data port resource (for example, USB or RS2) for realizing the interface 235.
32C). In short, the technology used to implement the functionality of the present invention is the target implementation cost,
It depends on factors such as the complexity and diversity of the interrupt source and the nature of the network from which raw packets are sent in response to remote interrupts.

It is intended that the scope of the invention be limited not by the detailed description of the present application, but rather by the appended claims. (Supplementary Note 1) A method for processing a remote interrupt signal, comprising: receiving an interrupt signal from an interrupt signal source at a remote node; and generating a raw packet including an interrupt signal source identifier based on the received interrupt signal. A method comprising the steps of selecting and issuing selected raw packets from a remote node to a host node over a network. (1) (Supplementary note 2) The method according to supplementary note 1, wherein the interrupt signal source is an event generated in the remote node, and the interrupt signal is an indication of the event. (Supplementary note 3) The supplementary note 1, wherein the selecting step further includes a step of repeating the selecting step a plurality of times until the raw packet becomes available in response to the raw packet associated with the received interrupt signal being unavailable. The described method.
(Supplementary note 4) The method according to Supplementary note 1, wherein the step of issuing is achieved by embedding the selected raw packet in a network packet and forwarding the network packet to the host node via the network. (Supplementary note 5) The method according to supplementary note 4, wherein the network packet includes an address associated with the host and a request associated with the received interrupt signal. (Supplementary Note 6) Based on the response received from the host node,
The method of claim 1, further comprising determining a state of the issued raw packet. (Supplementary note 7) The method according to Supplementary note 1, further comprising increasing a retry counter in response to the issued raw packet being rejected. (Supplementary note 8) The method according to supplementary note 7, further comprising the step of recording an error in response to the retry counter being at the maximum allowable value. (Supplementary Note 9) The method further includes recording an error in response to the issued raw packet being rejected.
The method according to supplementary note 1. (Supplementary note 10) The method according to supplementary note 1, further comprising the step of indicating a timeout condition in response to receiving no response from the host node regarding the issued raw packet. (Supplementary Note 11) A system for issuing a raw packet via a network in response to a remote interrupt, comprising:
A host node operatively coupled to the network for receiving the issued raw packets, including a processing unit; a network interface module and an interrupt signal source, based on the interrupt signal received from the interrupt signal source. A remote node for issuing a raw packet including an identifier of an interrupt signal source. (Supplementary note 12) The supplementary note, wherein the remote node includes a number of various interrupt signal sources, each interrupt signal source being associated with at least one raw packet stored in the remote node's network interface module. 12. The system according to 11. (Supplementary note 13) The network interface system, wherein a raw packet buffer for storing a number of raw packets, wherein each raw packet includes an identifier of a corresponding interrupt signal source, and the interrupt signal source outputs an interrupt signal. A network interface system comprising a raw packet buffer, wherein the network interface system issues corresponding raw packets to a host node via a network in response to supplying the network interface system. (Supplementary Note 14) An interrupt signal input operatively coupled to several interrupt signal sources, and a raw packet select output operatively coupled to a raw packet buffer, wherein the interrupt from the interrupt signal source is provided. 14. The system of claim 13, further comprising a processor for receiving the signal and selecting a raw packet stored in the raw packet buffer based on the received interrupt signal. (6) (Supplementary note 15) A packet assembler having a selected raw packet input and a network output, embedding the selected raw packet in a network packet, and issuing the network packet to the host node via the network. 15. The system of claim 14, further comprising: (Supplementary note 16) The system of Supplementary note 15, wherein the packet assembler has a request input operatively coupled to a request output of the processor, and wherein the network packet includes a request related to the received interrupt signal. . (Supplementary note 17) The system according to supplementary note 14, further comprising a packet receiver having a network input and a status output, for determining a status of the issued raw packet based on a response received from the host node. (8) (Supplementary note 18) In response to the issued raw packet being associated with a reject condition, the processor increments a retry counter for tracking unsuccessful transfer attempts of the issued raw packet. 15. The system according to claim 14, wherein
(9) (Supplementary note 19), wherein the processor records an error in response to the retry counter being at a maximum allowable value;
The system according to attachment 18. (Supplementary note 20) The system of Supplementary note 14, wherein the processor logs an error in response to the issued raw packet being associated with a rejected condition. (Supplementary note 21) The system according to supplementary note 14, wherein the processor indicates a time-out state in response to receiving the no response from the host node. (Supplementary note 22) The system according to supplementary note 13, wherein the raw packet is prepared in the host node in advance, and the prepared raw packet is supplied to the raw packet buffer. (10)

[Brief description of the drawings]

FIG. 1 is a block diagram of a system for sending raw packets in response to a remote interrupt according to one embodiment of the present invention.

FIG. 2 is a schematic block diagram of a remote network interface system according to an embodiment of the present invention.

FIG. 3 is a detailed block diagram of a remote network interface system according to an embodiment of the present invention.

FIG. 4 is a first half of a flowchart illustrating a method for processing a remote interrupt signal according to an embodiment of the present invention.

FIG. 5 is a second half of a flowchart illustrating a method for processing a remote interrupt signal according to one embodiment of the present invention.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Jeffrey Dee Larson United States, California 95125, San Jose, Roboway 1029 (72) Inventor Takeshi Horie United States, California 94304, Palo Alto, Sand Hill Road 1700, Number 205 F-term ( Reference) 5B045 BB28 BB42 FF03 5B098 AA10 BA11 BB11

Claims (10)

[Claims] 1. A method for processing a remote interrupt signal, comprising: receiving an interrupt signal from an interrupt signal source at a remote node; and a raw packet including an interrupt signal source identifier based on the received interrupt signal. And issuing the selected raw packet from the remote node to the host node via the network. 2. The method of claim 1, wherein the selecting step further comprises: repeating the selecting step a plurality of times in response to the raw packet being unavailable associated with the received interrupt signal until the raw packet becomes available. 2. The method according to 1. 3. The method of claim 1, further comprising determining a status of the issued raw packet based on a response received from the host node. 4. A system for issuing raw packets over a network in response to a remote interrupt, the system including a processing unit and operatively coupled to the network for receiving the issued raw packets. A remote node for issuing a raw packet including an interrupt signal source identifier based on the interrupt signal received from the interrupt signal source, the remote node including a network interface module and an interrupt signal source. system. 5. A network interface system, comprising: a raw packet buffer for storing a number of raw packets, wherein each raw packet includes an identifier of a corresponding interrupt signal source; Network interface system comprising a raw packet buffer, wherein the network interface system issues a raw packet corresponding to the host node via the network in response to supplying the raw packet buffer to the network interface system. 6. An interrupt signal input operatively coupled to a number of interrupt signal sources and a raw packet select output operatively coupled to a raw packet buffer, wherein the interrupt signal from the interrupt signal source is provided. The system of claim 5, further comprising a processor for selecting a raw packet stored in a raw packet buffer based on a received and received interrupt signal. 7. A packet assembler having a selected raw packet input and a network output, embedding the selected raw packet in a network packet, and issuing a network packet to the host node via the network. The system of claim 6, comprising a system. 8. It has a network input and a status output,
The system of claim 6, further comprising a packet receiver for determining a status of the issued raw packet based on a response received from the host node. 9. In response to the issued raw packet being associated with a rejection condition, the processor increments a retry counter for tracking unsuccessful transfer attempts of the issued raw packet. The system according to claim 6. 10. The system according to claim 5, wherein raw packets are prepared in a host node, and the prepared raw packets are supplied to a raw packet buffer.